Effects Of Polysaccharide Extracts From Sporophyll Of Undaria Pinnatifida And Its By-Products On Cookies Quality

As the main active component of spores of Undaria pinnatifida,the brown algae polysaccharide extract is continuously developed in the field of functional food.At the same time,the byproduct of the extraction of polysaccharide,such as spore leaf residue of Undaria pinnatifida,is usually discarded,causing environmental pollution and waste of a large amount of resources.But these abandoned residues have certain potential utility and economic value.The high-fat baked foods represented by cookies,which are exposed to air,are prone to lipid oxidation,shortening the shelf life of products,and reducing the nutritional value and safety of foods.In order to improve this type of bakery products,in this study,polysaccharides extract from sporophyll of Undaria pinnatifida?PESUP?and its by-products?PESUPPB?were used as functional ingredients instead of part of the flour,respectively added to the baked goods represented by cookie.The first part is the preparation of two kinds of cookies and the determination of active ingredients such as total sugar and total polyphenols.Meanwhile,the hardness,friability and color of cookie were measured and sensory evaluation.The second part is to study the storage stability of two kinds of cookies respectively.After 4 weeks of storage,the antioxidant activity of DPPH·free radical scavenging ability,ABTS·radical scavenging ability and Fe²⁺ion reducing ability of the cookie extract were measured.The TBARS value?MDA content?were measured by thiobarbituric acid method;The oxidation stability of cookies during 4 weeks of storage was monitored by electron spin resonance spectroscopy?ESR?and the contents of fatty acids in the samples were determined by gas chromatography-mass spectrometry?GC-MS?.The results showed that the cookies with the highest total sugar content and total phenol content were present in the two diets containing 5%?w/w?PESUP and 5%?w/w?PESUPPB,respectively.However,the addition of high levels of PESUP and PESUPPB can affect cookie quality parameters,causing significant differences in cookie color and increased cookie hardness.Sensory evaluation showed that the incorporation of both additives had a slight adverse effect on the organoleptic properties of the cookies but performed well in appearance and texture at the 0.5%?w/w?addition level,which could be accepted by the consumer.The free radical scavenging activity of 0.5%?w/w?PESUP cookie and 0.5%?w/w?PESUPPB cookie extract stored for 4 weeks was determined.During the storage period of 4weeks,the antioxidant activity of cookies decreased.However,compared with the control,the addition of polysaccharide extract of Undaria pinnatifida and its processing by-products enhanced the antioxidant activity in cookie.At the same time,the TBARS,fatty acid composition and lipid free radical content?ESR?of cookies were determined.It can be seen that with the extension of storage period,the addition of PESUP and PESUPPB respectively inhibited the lipid oxidation of cookie and maintained the quality of cookie.Based on the above studies,the extraction of polysaccharide from sporophyll of Undaria pinnatifida and its processing by-products have a positive effect on cookies.Innovative development of active ingredients-rich by-products can increase economic value and reduce waste generation.In addition,the final product of PESUP and PESUPPB can meet consumer expectations for health functional foods.